Malaria During Pregnancy Could Bolster Babies' Immunity

A mother and baby from the village of Pomerini, Tanzania. It's estimated that the disease kills 60,000 to 80,000 people there annually. (Credit: Franco Valpato/Shutterstock) You have a bit of your mother in you, literally. When scientists performed biopsies of young adults’ organs, they’ve found maternal cells embedded in hearts, kidneys, and liver. This phenomenon, called microchimerism, is caused by a small number of cells passing through the placenta during pregnancy. The transfer goes both ways, and scientists think it’s like a meet-and-greet between mom and fetus, preventing their immune systems from treating each other’s cells as dangerous invaders. But that doesn’t explain why these cells stick around long after birth.